Evlo Periya saavi?

I have always been wondering why the house keys in bangalore are so BIG
Does it provide additional security?
I have moved to some 3 different houses and all the houses had similar keys(size)
Its a pain to carry such a big key always :-(
This picture contains my bike key as well. In comparison see how big the house key is!!!!!!!
P.S. Picture taken from my Nokia 6230